Does immunohistochemistry provide additional prognostic data in gastrointestinal stromal tumors?

Multiple Metastatic Extra-gastrointestinal Stromal Tumors with Plasmoid Differentiation: A Case Report and Review of Literature

Extra-gastrointestinal stromal tumors (EGISTs) are rare mesenchymal tumors that arise from the abdominal, pelvic or retroperitoneal region, unrelated to the gastrointestinal tract. However, cases with a plasmoid morphology are extremely rare. we hererin report a 49-year-old man with abdominal pain who underwent magnetic resonance imaging that revealed an irregular tumor (103×71 mm) in size, in the space between stomach and pancreas, diagnosed as an EGISIT, we also reviewed the clinicopathological characteristics and immunohistochemical characteristics, molecular genetic features and differential diagnoses previously reported in the literature.

Ki67 for evaluating the prognosis of gastrointestinal stromal tumors: A systematic review and meta‑analysis

Overexpression of Ki67 is observed in tumor cells, and it has been suggested to be a marker for cancer prognosis. However, the relationship between Ki67 expression and the risk of recurrence of gastrointestinal stromal tumors (GISTs) remains poorly defined. In the present study, a meta-analysis was used to examine the associations between Ki67 levels and GIST recurrence. Studies reporting GIST and Ki67 were found by searching Cochrane Library, PubMed and Embase until October 14, 2021. The Newcastle-Ottawa Scale (NOS) was used to verify the quality of the evidence. Totally, 1682 patient cases were included. The odds ratio (OR) estimates and 95% confidence interval (CI) for each publication were determined by a fixed-effects (Mantel-Haenszel) model. A total of 20 studies that fulfilled the inclusion criteria were finally included in the analysis. The average score of quality evaluation was 6.4 points according to NOS. It was found that Ki67 levels were significantly higher in the NIH L group compared with the NIH VL group (OR: 0.51; 95% CI: 0.26-0.99; P=0.04; P heterogeneity=0.44). There was also greater Ki67 overexpression in the NIH I group compared with the NIH L group (OR: 0.45, 95% CI: 0.31-0.65; P<0.0001; P heterogeneity=0.32), while Ki67 levels were greater in the NIH H group than in the NIH I group (OR: 0.20; 95% CI: 0.15-0.28; P<0.00001; P heterogeneity=0.56). In conclusion, Ki67 overexpression may be a useful marker of the risk of recurrent GIST transformation.

CT Radiomics for the Preoperative Prediction of Ki67 Index in Gastrointestinal Stromal Tumors: A Multi-Center Study

Purpose

This study established and verified a radiomics model for the preoperative prediction of the Ki67 index of gastrointestinal stromal tumors (GISTs).

Materials and Methods

A total of 344 patients with GISTs from three hospitals were divided into a training set and an external validation set. The tumor region of interest was delineated based on enhanced computed-tomography (CT) images to extract radiomic features. The Boruta algorithm was used for dimensionality reduction of the features, and the random forest algorithm was used to construct the model for radiomics prediction of the Ki67 index. The receiver operating characteristic (ROC) curve was used to evaluate the model’s performance and generalization ability.

Results

After dimensionality reduction, a feature subset having 21 radiomics features was generated. The generated radiomics model had an the area under curve (AUC) value of 0.835 (95% confidence interval(CI): 0.761–0.908) in the training set and 0.784 (95% CI: 0.691–0.874) in the external validation cohort.

Conclusion

The radiomics model of this study had the potential to predict the Ki67 index of GISTs preoperatively.

Clinical outcomes of upper gastrointestinal bleeding in patients with gastric gastrointestinal stromal tumor

BACKGROUND

Upper gastrointestinal bleeding (UGIB) is one of the major manifestations of gastrointestinal stromal tumor (GIST) of the stomach. Several studies have reported that GIST bleeding is associated with poor prognosis. However, only case reports have reported hemostasis modalities for treating hemorrhagic gastric GIST. To identify clinical outcome of gastric GIST bleeding, we analyzed risk factors and prognosis of hemorrhagic GIST evaluating hemostasis methods.

METHODS

Total 697 patients histopathologically diagnosed with primary gastric GIST between January 1998 and May 2015 were enrolled to the study, retrospectively.

RESULTS

Of 697 total patients, 46 (6.6%) patients had UGIB. Endoscopic intervention, transarterial embolization, or surgical intervention was performed for initial hemostasis in 15, 2, and 1, respectively. Over a median of 68 months of follow-up, 16 patients in bleeding group and 88 patients in non-bleeding group died; the 5-year survival rate was 79.4% in bleeding group and 91.8% in non-bleeding group (p = 0.004). Multivariate analysis showed that significant risk factors for gastric GIST bleeding included the maximal tumor diameter > 5 cm and Ki-67 positivity. Age ≥ 60 [hazard ratio (HR) = 8.124, p = 0.048], necrosis (HR = 5.093, p = 0.027), and bleeding (HR 5.743, p = 0.034) were significant factors for overall survival of gastric GIST patients.

CONCLUSIONS

Bleeding risk of gastric GIST was higher when tumor had diameter > 5 cm or Ki-67 positivity. In addition, tumor bleeding, necrosis, and age ≥ 60 years were associated with poor overall survival. Endoscopic intervention can be considered as an effective method for initial hemostasis of hemorrhagic gastric GIST.

Ki67 is a biological marker of malignant risk of gastrointestinal stromal tumors: A systematic review and meta-analysis

BACKGROUND

Ki67 is a good marker of cell proliferation in a variety of tumors. High ki67 levels are usually associated with poor prognosis. However, the relationship between Ki67 expression and the risk of malignancy of gastrointestinal stromal tumors (GISTs) is still poorly defined. The current meta-analysis was initiated to address this issue.

METHODS

Studies reporting Ki67 expression and the risk of malignancy in GIST were found by searching Cochrane Library, PubMed, Medline, and Embase until October 31, 2016. A total of 9 studies involving 982 patients were included. Pooled odds ratio (OR) estimates and 95% confidence intervals (CIs) were calculated using a fixed-effect model.

RESULTS

Meta-analysis showed no significant difference in the incidence of Ki67 overexpression between the very low NIH group and the low NIH group (OR: 0.66, 95% CI: 0.25-1.76; P = .41, Pheterogeneity = .25). However, the incidence of Ki67 overexpression gradually increased from the low NIH group to the high NIH group (OR: 0.46, 95% CI: 0.27-0.80; P = .005, Pheterogeneity = .13) and (OR: 0.22, 95% CI: 0.15-0.34; P < .00001, Pheterogeneity = .33).

CONCLUSIONS

There were more GIST patients with Ki67 overexpression in the intermediate and high NIH groups than in the low NIH group. Ki67 overexpression may be a useful marker of the risk of malignant GIST transformation.

Gastrointestinal Stromal Tumors: A Clinicopathologic and Risk Stratification Study of 255 Cases from Pakistan and Review of Literature

PURPOSE

To describe the clinicopathological features of gastrointestinal stromal tumors (GIST) diagnosed in our section and to perform risk stratification of our cases by assigning them to specific risk categories and groups for disease progression based on proposals by Fletcher et al and Miettinen and Lasota.

MATERIALS AND RESULTS

We retrieved 255 cases of GIST diagnosed between 2003 and 2014. Over 59% were male. The age range was 16 to 83 years with a mean of 51 years. Over 70% occurred between 40 and 70 years of age. Average diameter of tumors was 10 cms. The stomach was the most common site accounting for about 40%. EGISTs constituted about 16%. On histologic examination, spindle cell morphology was seen in almost of 85% cases. CD117 was the most useful immunohistochemical antibody, positive in 98%. Risk stratification was possible for 220 cases. Based on Fletcher's consensus proposal, 62.3 gastric, 81.8% duodenal, 68% small intestinal, 72% colorectal and 89% EGISTs were assigned to the high risk category; while based on Miettinen and Lasota's algorithm, about 48% gastric, 100% duodenal, 76% small intestinal, 100% colorectal and 100% EGISTs in our study were associated with high risk for disease progression, tumor metastasis and tumor related death. Follow up was available in 95 patients; 26 were dead and 69 alive at follow up. Most of the patients who died had high risk disease and on average death occurred just a few months to a maximum of one to two years after initial surgical resection.

CONCLUSIONS

Epidemiological and morphologic findings in our study were similar to international published data. The majority of cases in our study belonged to the high risk category.

Back to the start: Evaluation of prognostic markers in gastrointestinal stromal tumors

The aim of this study was to provide a standardized risk stratification model for gastrointestinal stromal tumors (GISTs) based on tumor localization, tumor size, involved lymph nodes and metastases, as well as mitotic activity and other morphological and molecular markers, in order to improve the risk evaluation scheme for recurrence, metastatic spread and survival for patients with GIST. A total of 201 cases of patients with GIST were investigated according to standardized morphological markers, including nuclear pleomorphism, tumor cell necrosis, mucosal infiltration, ulceration, skeinoid fibers and growth pattern. In addition, all cases were immunohistochemically analyzed using a tissue microarray platform for various markers of differentiation (CD34, CD44, CD117, desmin, discovered on GIST 1, platelet-derived growth factor receptor α, S-100 and smooth muscle actin) and proliferation (B-cell lymphoma 2, P16, P53, phosphohistone H3 and Ki-67). These findings were correlated by uni- and multivariable analyses with clinicopathological characteristics, including recurrence, metastasis and survival. The general clinicopathological parameters of this GIST specimen cohort were comparable to previous studies. While several parameters exhibited clear associations to each other and to the defined clinical endpoints, the multivariate analysis reduced the number of relevant prognostic variables to localization, margin status, growth pattern and hematoxylin and eosin-based mitosis/Ki-67-based proliferation of GISTs. With the exception of CD34, none of the applied markers of differentiation and proliferation were found to be independent prognostic markers in GIST and the classical risk factors of GIST remain important prognostic factors. Additionally, growth pattern may predict the risk of recurrence and metastasis in GIST patients. Additional independent molecular prognostic markers remain to be identified and validated.

Clinico-pathological characteristics and prognostic factors of gastrointestinal stromal tumors among a Chinese population

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms in the gastrointestinal tract, exhibiting wide variability in their biological behavior. The aim of the present study was to investigate the clinicopathological characteristics and prognostic factors of GISTs in Chinese patients. All GIST cases (n=182) retrieved from the pathology database and the archived files in Shanghai Changzheng Hospital between January 2011 and December 2014 were reviewed. The clinical symptoms, preoperative investigations, treatments, pathological characteristics and follow-up data of these patients were reviewed, and univariate and multivariate survival analyses were performed. A total of 73.1% of the GISTs were located in the stomach, and the most common three symptoms included abdominal pain (30.2%), dyspepsia (23.1%) and gastrointestinal bleeding (21.4%). Univariate analysis revealed that larger tumor size (P<0.001), higher mitotic rate (P<0.001), aggressive behavior (P<0.001), negative smooth muscle actin expression (P=0.009) and palliative resection (P<0.001) contributed toward poor overall survival (OS). In addition, non-gastric disease location (P<0.001), larger tumor size (P<0.001), higher mitotic rate (P=0.004), aggressive behavior (P<0.001) and palliative resection (P<0.001) were associated with poor relapse-free survival (RFS). Multivariate analysis indicated that mitotic rate [hazard ratio (HR=3.761, P=0.015)] and aggressive behavior (HR=3.916, P=0.010) were independent risk factors for OS, while non-gastric location (HR=4.740, P=0.002) and aggressive behavior (HR=4.009, P=0.004) were independent risk factors for RFS. The present study provided information on the clinicopathological characteristics and epidemiology of GISTs in the Chinese population. Non-gastric disease location, higher mitotic rate and tumor metastasis or local invasion prior to treatment were identified as predictors of a poor prognosis.

Giant gastrointestinal stromal tumour of rare sarcomatoid epithelioid subtype: Case study and literature review

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract, but they represent less than 3% of all gastrointestinal tract malignancies. This is a detailed case study of a 52-year-old male patient treated for very uncommon histological subtype of gastric GIST with atypical clinical presentation, asymptomatic progress and late diagnosis. The resected tumour, giant in diameters, was confirmed to represent the most rare histopathologic subtype of GISTs - sarcomatoid epithelioid GIST. We report this case and review the literature with a special focus on pathomorphological evaluation, biological aggressiveness and prognostic factors. To our knowledge this is the first report of giant GIST of very uncommon sarcomatoid epithelioid subtype. It is concluded that clinicians should pay attention to the fact that initial diagnosis may be delayed due to mildly asymptomatic and non-specific clinical presentation. Asymptomatic tumours diagnosed at a late stage, which is often the case, can be large on presentation. Prognosis for patients diagnosed with GIST depend on tumour size, mitotic rate, histopathologic subtype and tumour location. That is why early diagnosis and R0 resection, which is usually feasible and safe even in giant gastric sarcomatoid epithelioid subtype of GISTs, are the key factors for further treatment and good prognosis.

Conservative surgery vs. duodeneopancreatectomy in primary duodenal gastrointestinal stromal tumors (GIST): a retrospective review of 114 patients from the French sarcoma group (FSG)

BACKGROUND

Duodenal GISTs represent 3-5% of all GISTs with limited understanding of patient outcomes. We conducted a retrospective analysis of primary localized duodenal GISTs.

METHODS

Patients were identified via a survey from 16 FSG centers (n = 105), and a group of 9 patients enrolled in the BFR14 trial. Data were collected from the original database and patient files, in agreement with French legislation.

RESULTS

114 patients were included, with a median age of 57. Tumors originated mainly in D2 (33%), or D3 (24%), with a median size of 5 cm. 109 patients had resection of the primary tumor; with a Local Resection (LR, n = 82), a pancreaticoduodenectomy (PD, n = 23), and data were missing for 4 patients. Resections were R0 (n = 87, 79%), R1 (n = 8, 7%), R2 (n = 6). Tumor characteristics were: KIT+ (n = 104), CD34+ (n = 58). Miettinen risk was low (n = 43), and high (n = 52). Imatinib was administered preoperatively (n = 11) and post-operatively (n = 20). With a median follow-up of 36 months (2-250), 98 patients are alive, and 33 relapsed. The 5-year OS and EFS rates are 86.5% and 54.5%. EFS was similar for patients in the LR and the PD groups (P > 0.05). In multivariate analysis, ECOG PS, and CD34 expression are independent prognostic factors on OS. Miettinen risk and spindle cell type are independent predictive factors for relapse.

CONCLUSIONS

Patients with resected duodenal GIST have a reasonably favorable prognosis. This study favors a preservation of pancreas when there are no anatomical constraints. LR exhibit similar survival and smaller morbidity then PD.